Chapter 6 Reasoning The discovery of Animal tool use o Jane Goodall studied chimps in the wild at Gombe Stream National Park Tanzania o Discovered that chimps use tools in the wild Blades of grass at termite mounds Used grass as tools to fish out termites Seen altering blades of grass making tools o Chimpanzees Clean themselves with wads of leaves Use them like a sponge to soak up water for drinking o In Republic of Congo chimps observed using tool kit a combination of tools to harvest termites Use feet to poke sticks in ground Use different sticks as fishing probes to remove termites Use teeth to fray end of probe like brush to collect more insects o Chimpanzees have learned to use poles to escape from enclosure One chimp spontaneously used the pole to obtain something Other chimps learned to use poles for escaping apparently by from a higher shelf imitation Important because Pole was not believed to be result of observing humans o Tool use in captive hooded monkeys Presented clear plastic tubs partially filled with yogurt Tubes were too small to probe with fingers and bolted to table Pieces of wood available in vicinity Hooded monkeys made spoons from the wood to extract the yogurt o Avian tool use Tool use in Egyptian vultures Use rocks to break open ostrich eggs Jane Goodall reported the vultures search as far as 50 yards from the egg in order to find a proper rock Forward jerking movement of vulture s head exhibited when breaking an egg with a stone is similar to movement when the bird pecks eggs to break them Other species of birds break eggs by throwing them down on stones o Not considered tool use because the stone is not used as an extension of the bird s body Alcock 1975 o Proposed vultures originally threw eggs to break them open later learning to throw rocks at eggs C R Thouless o Using rocks to break eggs may have begun by accidently hitting eggs with rocks o Vultures preferentially choose egg shaped stones to break eggs o Young vultures reared without exposure to adults throw stones at eggs behavior is innate o Vultures must first learn that ostrich eggs are a food source before the stone throwing is observed By tasting an egg cracked open by another bird Tool use and fabrication in woodpecker finches Woodpeckers can use their long barbed tongues to extract grubs from branches without the assistance of a tool Woodpecker finches o Live in Galapagos Islands o Have short beak and tongue o Fabricate tools from cactus spines Harvest grubs from recesses in tree branches Carry the tool and re0use it Milikan and Bowman 1967 o Caged different species of finches from the Galapagos Islands next to woodpecker finches o Large cactus ground finches Do no normally use tools but acquired similar tool use when caged next to woodpecker finches o Other species of finches Have not been shown to be able to learn to use tools when they were caged next to the woodpecker finch Woodpecker finch tool making o In captivity shortening long cactus spines o In the wild snapping off parts of twigs to make tools similar to cactus spines Beck 1980 Tool Use in a Crow Crow lived in Beck s Laboratory o Normally fed dried mash moistened so the crow could pick it up to eat it o Toy cup provided o When unmoistened mash was presented crow learned to use the cup to collect water to moisten the mash New Caledonian Crow Wire left get food pail bends hook and hooks the pail to get the food Green Herons Using Bait Occasionally observed bait fishing o Dropping small objects on the surface of water to attract fish to swim to the surface Bait fishing is rare o Suggests it is not an innate behavior o Suggests the behavior is not culturally Umbrella Bird Black Egret Fishing transferred Fish naturally like dark areas when in fear Go under umbrella and Black Egret catches them o The meaning of tool use in animals Does the ability to use tools signify an intelligence level close to that of humans Intelligence as the ability to adapt to the environment as proposed by Romanes Tool use in primates may shed light on the abilities and lifestyles of early humans What conditions are necessary for animal tool use 2 characteristics of an environment are necessary to support the evolution of tool behaviors in animals It has been proposed that o Tool use must be advantageous to the animal o Tool use depends on the availability of objects in the environment which make feasible tools o Tool use occurs more often in captive animals Tool use more prevalent in captive birds and mammals than in their wild counterparts Environmental opportunity Captive animals have o Fewer chores to survive o Typically more objects to manipulate enrichment o Some remaining questions How do animals learn to use tools Trial and error Reasoning Imitation How widespread is tool use in different species Harder Must come to a conclusion of what is going on in the brain science behind the reasoning Reasoning by analogy o Transitive inference Inferential reasoning deriving logical conclusions from known facts Transitivity whenever an element a is related to an element b by a transitive rule and b has the same relationship to an element c then a is also related by the same transitive rule to c Ex If 1 2 and 2 3 you can infer 1 3 Transitive inference demonstrated by inferring the order of a set of stimuli based on experience with only 2 stimuli at a time Transitive inference in Chimps Gillan 1981 Can chimp learn abstract relationships like A B C D E o 2 jars with differenct colored lids 1 has a treat o right vs left reinforcement changes Red Green Green Yellow Yellow Blue Blue Orange o Chimps do well on test Does passing this test prove that chimps use abstract inferential reasoning o Monkeys pass the test too McGonigle Chalmers o Rats pass the test too o So do pigeons Morgan s canon Is there another simpler explanation of these animals behavior Transitive Inference and Value transfer Fersen Wynne Delius Staddon Value transfer a nonreinforeced stimulus presented with a reinforced stimulus will gain some value through generalization In B vs D test B is chosen because it has more balue than D So which animals reason and which animals respond to value transfer o Animals that reason primates parrots o Animals that do not reason pigeons o Unsure Rats other mammals other birds o Analogical reasoning in chimps Analogical reasoning reasoning by analogy Miller s Analogy test Example car road train car is to road as train is to what Gillan et al 1981 Perceptual